Typical automatic water heater tanks are normally provided with cold and hot water connections and a relief valve connection at the top of the tank, a drain valve connection at the bottom of the tank, and an integral source of heat for heating the water. When it is desired to provide an external source of hot water for the tank, a T-fitting may be inserted between the drain connection and the drain valve for withdrawing relatively cold water from the bottom of the tank and this cold water passes to an external source of heat and the heated water from the external source moves back to the tank. A T-fitting may be provided between the relief valve connection in the tank and the relief valve for passage of the external hot water into the tank. However, in such an installation the relief valve may be actuated by the temperature of the external hot water while the overall temperature of the water in the tank is far below the temperature at which the valve is actuated.
This invention, in brief, is directed to a hot water installation and a fluid handling assembly comprising a pair of nested tubes spaced apart for receiving a fluid therebetween. Adjacent open portions of the tubes provide for fluid flow within a tank, or the like, and second open portions of the tubes are sealed from each other to provide separate flow paths for the fluid outside the tank. In one embodiment, the outer tube is connected into a water tank and provides an outlet for relatively cold water in the tank, and the inner tube extends from this outlet farther into the tank and provides an inlet for hot water into the tank, the arrangement being such as to effectively retard the hot water from mixing with the cold water entering the inlet. Outside the tank the outer or cold water tube is connected through a pump for circulating the cold water through a source of heat such as a solar collector, an air conditioning condenser, or similar heat generating equipment, and circulating the resultant hot water from the source through the inner tube and into the tank. In a typical water heater tank, the outer tube is preferably connected into the existing drain connection and is provided with a drain valve for draining the tank. By introducing the external supply of hot water into a lower portion of the tank, premature operation of the typical relief valve in an upper portion of the tank is effectively prevented since the external hot water mixes with cooler water in the tank and is not immediately exposed to the relief valve as would occur if the external hot water is introduced directly into the top of the tank.
Numerous patents shows nested tubes in fluid handling assemblies, for example as show in U.S. Pat. Nos. 638,195, 1,143,196 and 3,267,993, but in all of these patents fluid passing through the nested tubes is moving in the same direction through each of the tubes. A patent showing nested tubes in which fluid flows in opposite directions through the tubes is U.S. Pat. No. 2,224,403, but this patent is not particularly concerned with fluid at different temperatures, and closely proximate openings of the nested inlet and outlet tubes is of no particular consequence. A patent of passing interest for a showing of using transformer cooling water for supplying hot water to a residence is shown in U.S. Pat. No. 3,212,563, and simply suggests another source of external hot water which could be used in conjunction with the fluid handling assembly of this invention.
It is an object of this invention to provide a new and useful hot water installation including a container such as a hot water tank having a pair of nested tubes transversely spaced apart for receipt of water therebetween, an outer one of the tubes being connected into the tank, and the tubes having first open portions opening into the tank and second open portions sealed from each other outside the tank. A related object is provision of such an installation in a tank having a drain connection for receiving a drain in a normal installation of the tank, and the outer tube being connected into the drain connection. Another related object is provision of one of these tubes having a third open portion independent of its first and second open portions, and the third open portion communicating with a drain for the tank. Another related object provision of the first open portions of the tubes (within the tank) being longitudinally spaced from each other, the first open portion of the outer tube being proximate the drain connection of the tank and the first open portion of the inner tube opening into the tank inwardly of the drain connection.
Another object is provision of a fluid handling assembly including a pair of nested tubes, the tubes being transversely spaced apart for receipt of a fluid therebetween, each of the tubes having first and second open portions, the first open portions being longitudinally spaced from each other. A related object is provision of one of the tubes having a third open portion independent of its first and second open portions.
Still another object is to provide a new and useful fluid handling assembly. A related object is provision of such an assembly having inner and outer tubes, one of the tubes providing an inlet for fluid and the other of the tubes providing an outlet for the fluid. Still another related object is provision of such an assembly for replacing a typical drain valve of a container such as a water tank by connecting the outer tube into the tank drain connection and providing the outer tube with a drain valve, with ends of the tubes outside the tank being sealed from each other to provide separate paths for water leaving the tank and for water entering the tank. Still another related object is the provision for the outer tube receiving relatively cold water from the tank and connected for circulating the cold water through an external source of heat for heating the water, the heated water being returned through the inner tube into a lower portion of the tank.
These and other objects and advantages of the invention will be apparent from the following description and accompanying drawing.